Caption:Small hydropower projects are a way to continue to sustain and implement a renewable energy option without causing the damage to ecosystems, environments, and local communities and the countering of carbon footprint like large-scale, big hydropower plants do.
Small Hydropower Projects:
In contrast to small hydropower projects, large scale hydropower reservoirs and dams cause negative environmental impacts that most people don’t realize. Hydroelectric plants work by using kinetic energy in lakes, reservoirs, and rivers to drive large water turbines. The structure of these facilities is simple; on the reservoir side there is an intake valve that brings the water through a shaft to the turbine. The blades of the turbine spin to create energy as the water flows out the other side into a river or stream.
What ends up having a negative environmental impact is when these plants are erected on a large scale. In order to create a reservoir to have a constant pool of water to rush through a hydroelectric system, a dam must be put into place. Damming rivers cause water to over spill into the surrounding environments, disrupting natural habitats as the water forms a new basin for itself. According to the text book Silenced Rivers: The Ecology and Politics of Large Dams, “the permanent inundation of forests, wetlands, and wildlife is [one of the] most obvious ecological effects of a dam. At least 400,000 square kilometers have been lost worldwide to flooding due to reservoirs.” Additionally, as the plants on the once fertile riverbanks flood and die, they begin to rot and decompose. This releases carbon into the atmosphere while the decaying plant matter sinks. Excess decaying plant matter contributes to the non-oxygenated non-flowing water making conditions for underwater wildlife difficult and leading to the degradation of biomass which eventually produces dissolved methane, a recognized greenhouse gas. Also, reservoirs stop the rivers from carrying useful sediment downstream for the formation of riverbanks, river deltas, levees, and coastal shores. Natural river barriers are important; Hurricane Katrina, for example, might not have been so devastating if the Mississippi River Delta had been replenished with silt rather than being dammed further upstream. The silt and sediment instead of traveling downstream, stays in the reservoir, building up over time. This buildup causes reduced water-storage capacity and if not addressed might eventually result in expiration of the dam and river. Dams and the creation of reservoirs sometimes require the relocation of large human populations if constructed nearby residential areas.
What could be a potential solution to the damaging and lasting effects of large hydroelectric plants would be increased implementation of their smaller-scale counterparts. Small hydropower projects can tap into a river’s energy without causing long-lasting environmental changes to the area. This is because they use energy from “run of the river” tactics that don’t require dams. There is no damming or flooding, silt and sediment along with wildlife can still travel freely downstream. Small hydropower projects are defined by generating anywhere between 1MW (megawatt) and 30MW of energy, whereas anything more that 30MW is considered large. To put it into perspective, the Hoover Dam which plugs up the Colorado River generates about 2000MW.
According to a report compiled in 2006 by the Idaho National Laboratory, there are approximately 130,000 streams in the United States that are suitable for projects between 10kW and 30MW. These projects could increase US hydroelectric generation by more than 50%. Most small hydropower plants provide energy for local communities, eliminating any sort of energy loss through long transport. Also by engaging locals, these projects contribute to community resilience by distributing the responsibility of energy generation. More connectivity to the source of energy might encourage people to be more aware of their energy consumption. After all, almost 8% of global carbon emissions come from American households (Cooney).
There are also creative alternatives to large traditional hydropower plants. Lifetime inventor Johann Hoffman designed a way to harness river power using suspended turbine structures placed in the middle of a flowing river. The turbine blades function similarly to that of a hydropower plant in that energy is generated by the spinning of the turbine as the water flows through it. Benefits of this design include no silt or sediment build up, rivers maintain their ecological balance, absolutely no carbon emissions, and considerably lower costs than its dam and power plant counterparts. Also this design can be placed anywhere.
I am not proposing to completely remove large hydropower plants from our renewable energy options; I am suggesting we look at smaller hydropower projects to avoid complications being faced from current and past projects. We can mitigate the effects of large scale dams by becoming more reliant on small scale projects.
1.McCully, Patrick. "Rivers No More: The Environmental Effects of Large Dams | International Rivers." International Rivers. Creative Commons, 2001. Web. 09 Dec. 2011. <http://www.internationalrivers.org/node/1636>. 2. Patrick McCully is the Director of the Berkeley, California-based International Rivers Network (IRN). He is an editorial advisor for the International Journal on Water and a member of EcoEquity, an organization that promotes an international climate treaty based on equal per capita rights to the atmposphere. 3. The main topic of the excerpt is how large dams disturb a river’s ecology. 4. The text breaks the problem into comprehensive impacts: impacts during construction and impacts during operation. The text uses examples of dams that have caused environmental disruption. 5. (a)“As every river is unique…so the design and operating pattern of every dam is unique, as are the effects the dam has on the river and its associated ecosystems” Mahaweli megascheme in Sri Lanka, the main purpose of which is to expand irrigation in previously forested areas, (b) “The five-dam has submerged and turned into agricultural land the habitat of seven endangered and two threatened animal species…” (c) “As well as flooding and fragmenting some of the world’s best wildlife habitats, reservoirs have also inundated some of the world’s most beautiful and spectacular river scenery”
6. In my research of a sustainability problem to fix, this supported the negative effects of large scale hydropower projects.
7. I used a fact mentioned: 400,000 square kilometers have been lost worldwide to reservoir flooded areas. I also found information about the displacement of human communities during the building of a dam.
1."Small Hydro: New Research Initiative to Enable Further Opportunities. « Commercial Climate." Commercial Climate. WordPress.com, 3 Aug. 2011. Web. 09 Dec. 2011. <http://climatecommercial.wordpress.com/2011/08/03/small-hydro-new-research-initiative-to-enable-further-opportunities/>. 2. There was no author disclosed. 3. The main topic of the text is how new research has gone into proving that small hydropower projects are growing in popularity and have a projection of growth as well. Because they are technically and economically feasible, many people are looking to put investments in them. 4. The argument provides facts on in increase in small hydro investment according to multiple finance reports. It further identified the countries most interested in these projects and investments and used quotes from a water power plant representative. 5. “Small hydropower is experiencing significant growth rates. Industry analysis forecast a doubling of installed capacity of small hydropower in the next ten years.” (b) “Further primary research to test aquatic species for vulnerability would enable guidelines and standards for turbine design criteria to be established.” (c) “While this research is likely to require expansion and updating to include further species and particularities – including for marine purposes – it has the real potential to kick-start an important and growing sustainable energy niche with global application potential.” 6. This text supports my argument by proving that small scale hydro is becoming an increasingly more popular alternative to larger scale, more damaging projects. It proves research is being done and that this topic is relevant and current. 7. I used this article in my collage; there was a graph that showed the past and projected growth of small scale hydro. This text also explained a lot about turbines currently being researched which helped my understanding of their purpose in hydropower.
Caption: Small hydropower projects are a way to continue to sustain and implement a renewable energy option without causing the damage to ecosystems, environments, and local communities and the countering of carbon footprint like large-scale, big hydropower plants do.
Small Hydropower Projects:
In contrast to small hydropower projects, large scale hydropower reservoirs and dams cause negative environmental impacts that most people don’t realize. Hydroelectric plants work by using kinetic energy in lakes, reservoirs, and rivers to drive large water turbines. The structure of these facilities is simple; on the reservoir side there is an intake valve that brings the water through a shaft to the turbine. The blades of the turbine spin to create energy as the water flows out the other side into a river or stream.
What ends up having a negative environmental impact is when these plants are erected on a large scale. In order to create a reservoir to have a constant pool of water to rush through a hydroelectric system, a dam must be put into place. Damming rivers cause water to over spill into the surrounding environments, disrupting natural habitats as the water forms a new basin for itself. According to the text book Silenced Rivers: The Ecology and Politics of Large Dams, “the permanent inundation of forests, wetlands, and wildlife is [one of the] most obvious ecological effects of a dam. At least 400,000 square kilometers have been lost worldwide to flooding due to reservoirs.” Additionally, as the plants on the once fertile riverbanks flood and die, they begin to rot and decompose. This releases carbon into the atmosphere while the decaying plant matter sinks. Excess decaying plant matter contributes to the non-oxygenated non-flowing water making conditions for underwater wildlife difficult and leading to the degradation of biomass which eventually produces dissolved methane, a recognized greenhouse gas. Also, reservoirs stop the rivers from carrying useful sediment downstream for the formation of riverbanks, river deltas, levees, and coastal shores. Natural river barriers are important; Hurricane Katrina, for example, might not have been so devastating if the Mississippi River Delta had been replenished with silt rather than being dammed further upstream. The silt and sediment instead of traveling downstream, stays in the reservoir, building up over time. This buildup causes reduced water-storage capacity and if not addressed might eventually result in expiration of the dam and river. Dams and the creation of reservoirs sometimes require the relocation of large human populations if constructed nearby residential areas.
What could be a potential solution to the damaging and lasting effects of large hydroelectric plants would be increased implementation of their smaller-scale counterparts. Small hydropower projects can tap into a river’s energy without causing long-lasting environmental changes to the area. This is because they use energy from “run of the river” tactics that don’t require dams. There is no damming or flooding, silt and sediment along with wildlife can still travel freely downstream. Small hydropower projects are defined by generating anywhere between 1MW (megawatt) and 30MW of energy, whereas anything more that 30MW is considered large. To put it into perspective, the Hoover Dam which plugs up the Colorado River generates about 2000MW.
According to a report compiled in 2006 by the Idaho National Laboratory, there are approximately 130,000 streams in the United States that are suitable for projects between 10kW and 30MW. These projects could increase US hydroelectric generation by more than 50%. Most small hydropower plants provide energy for local communities, eliminating any sort of energy loss through long transport. Also by engaging locals, these projects contribute to community resilience by distributing the responsibility of energy generation. More connectivity to the source of energy might encourage people to be more aware of their energy consumption. After all, almost 8% of global carbon emissions come from American households (Cooney).
There are also creative alternatives to large traditional hydropower plants. Lifetime inventor Johann Hoffman designed a way to harness river power using suspended turbine structures placed in the middle of a flowing river. The turbine blades function similarly to that of a hydropower plant in that energy is generated by the spinning of the turbine as the water flows through it. Benefits of this design include no silt or sediment build up, rivers maintain their ecological balance, absolutely no carbon emissions, and considerably lower costs than its dam and power plant counterparts. Also this design can be placed anywhere.
I am not proposing to completely remove large hydropower plants from our renewable energy options; I am suggesting we look at smaller hydropower projects to avoid complications being faced from current and past projects. We can mitigate the effects of large scale dams by becoming more reliant on small scale projects.
Sources:
http://www.good.is/post/why-small-hydropower-beats-big-dams/
http://www.businessweek.com/globalbiz/content/dec2009/gb2009127_163138.htm
http://thinkprogress.org/romm/2011/08/11/293918/small-hydro-has-strong-bi-partisan-support-so-why-cant-we-get-our-act-together/
http://www.renewableenergyworld.com/rea/news/article/2008/03/u-s-on-the-verge-of-a-small-hydro-boom-51858
http://en.wikipedia.org/wiki/Environmental_impact_of_reservoirs#cite_note-10
http://www.internationalrivers.org/node/1636
http://climatecommercial.wordpress.com/2011/08/03/small-hydro-new-research-initiative-to-enable-further-opportunities/
http://energybible.com/water_energy/large_hydro_systems.html
Annotations:
1.McCully, Patrick. "Rivers No More: The Environmental Effects of Large Dams | International Rivers." International Rivers. Creative Commons, 2001. Web. 09 Dec. 2011. <http://www.internationalrivers.org/node/1636>.
2. Patrick McCully is the Director of the Berkeley, California-based International Rivers Network (IRN). He is an editorial advisor for the International Journal on Water and a member of EcoEquity, an organization that promotes an international climate treaty based on equal per capita rights to the atmposphere.
3. The main topic of the excerpt is how large dams disturb a river’s ecology.
4. The text breaks the problem into comprehensive impacts: impacts during construction and impacts during operation. The text uses examples of dams that have caused environmental disruption.
5. (a)“As every river is unique…so the design and operating pattern of every dam is unique, as are the effects the dam has on the river and its associated ecosystems” Mahaweli megascheme in Sri Lanka, the main purpose of which is to expand irrigation in previously forested areas, (b) “The five-dam has submerged and turned into agricultural land the habitat of seven endangered and two threatened animal species…” (c) “As well as flooding and fragmenting some of the world’s best wildlife habitats, reservoirs have also inundated some of the world’s most beautiful and spectacular river scenery”
6. In my research of a sustainability problem to fix, this supported the negative effects of large scale hydropower projects.
7. I used a fact mentioned: 400,000 square kilometers have been lost worldwide to reservoir flooded areas. I also found information about the displacement of human communities during the building of a dam.
1."Small Hydro: New Research Initiative to Enable Further Opportunities. « Commercial Climate." Commercial Climate. WordPress.com, 3 Aug. 2011. Web. 09 Dec. 2011. <http://climatecommercial.wordpress.com/2011/08/03/small-hydro-new-research-initiative-to-enable-further-opportunities/>.
2. There was no author disclosed.
3. The main topic of the text is how new research has gone into proving that small hydropower projects are growing in popularity and have a projection of growth as well. Because they are technically and economically feasible, many people are looking to put investments in them.
4. The argument provides facts on in increase in small hydro investment according to multiple finance reports. It further identified the countries most interested in these projects and investments and used quotes from a water power plant representative.
5. “Small hydropower is experiencing significant growth rates. Industry analysis forecast a doubling of installed capacity of small hydropower in the next ten years.” (b) “Further primary research to test aquatic species for vulnerability would enable guidelines and standards for turbine design criteria to be established.” (c) “While this research is likely to require expansion and updating to include further species and particularities – including for marine purposes – it has the real potential to kick-start an important and growing sustainable energy niche with global application potential.”
6. This text supports my argument by proving that small scale hydro is becoming an increasingly more popular alternative to larger scale, more damaging projects. It proves research is being done and that this topic is relevant and current.
7. I used this article in my collage; there was a graph that showed the past and projected growth of small scale hydro. This text also explained a lot about turbines currently being researched which helped my understanding of their purpose in hydropower.